Might circumcision benefit gay men?

Most of the evidence suggests that circumcision is unlikely to
reduce HIV transmission between gay men. This is not unexpected, as more HIV is
likely to be acquired rectally than via the penis, but there is little evidence
that even ‘tops’ who exclusively practise insertive sex (or claim to) are
likely to benefit as a group, though there could be benefit on an individual
level.

The HIV Network for Prevention Trials Vaccine Preparedness Study
enrolled 3257 gay men in six US
cities from 1995 to 1997.1
This was a longitudinal study, and HIV incidence was 1.55 per 100 person-years
over 18 months of follow up. In this study, uncircumcised gay men were twice as
likely to become infected with HIV as circumcised men.

However, this was not a randomised controlled trial and, although
the results were suggestive, it could not rule out differences in behaviour
between circumcised and uncircumcised men as the cause.

One 2001 study2
explored the relationship between circumcision and HIV transmission in gay men
in Sydney, Australia. Between 1993 and 1999,
74 gay men were interviewed soon after being diagnosed with recent infection. Infection
assumed to be through insertive sex
comprised 15% of all infections. The researchers found no association between
circumcision status and infection by insertive unprotected anal intercourse.

A longitudinal Australian study of 1427 initially HIV-negative gay
men suggests that circumcision does not alter HIV incidence in gay men.3
At enrolment, 66% of cohort participants were circumcised. There were 49
seroconversions among cohort participants within the following five years: 29
(69%) in circumcised men and 13 in uncircumcised men, representing an incidence
of 0.80 per 100 patient-years. There was no difference in the incidence of HIV
infection between circumcised and uncircumcised men. This remained true when
the analysis controlled for age, anorectal STIs, and insertive or receptive
unprotected anal intercourse (UAI) with someone who was HIV-positive. The
incidence in men who reported no receptive UAI was halved (0.35 infections per
100 patient years), but this was not statistically significant.

Another 2007 study from the United States4
found no statistically significant evidence that being circumcised protects
against HIV infection amongst black or Latino men who have sex with men (MSM),
even amongst MSM who said they only practised insertive intercourse. This study
interviewed 1079 black and 957 Latino MSM in New York,
Philadelphia, and Los Angeles. They found that 74% of black MSM
were circumcised and 33% of Latino MSM.

The investigators note: “Circumcision conferred neither risk nor
protection among black men or Latino men in our study, however, and was
unrelated to seroconversion among MSM who reported that their last HIV test was
negative. Further, there was no evidence that circumcision was protective among
men who had only engaged in unprotected insertive anal sex in any of the
models.”

A
later meta-analysis of studies of circumcision in gay men and men who have sex
with men (MSM) by the same researchers found a small reduction in the risk of
HIV infection in circumcised men, but this was not statistically significant.5

The
meta-analysis covered 17 studies conducted between 1989 and 2007. The analysis
also included some unpublished results. The studies included 27,816 circumcised
and 25,751 uncircumcised men. Nine were conducted in North America, while four out of the other eight were
conducted in developing countries in Asia and South
America. Circumcision prevalence in individual studies varied from
4% to 88%.

Overall,
the studies reported a non-statistically significant reduction of 14% in HIV
infection for circumcised men. A subset of studies that looked at results in
2238 men who only had insertive sex found a 29% reduction in HIV infection
among circumcised men, but this difference was also not statistically
significant.

However,
in studies conducted prior to the introduction of effective HIV treatment, the
authors found a statistically significant 53% reduction in HIV infection in
circumcised men. They pointed out that this reduction was “comparable” to that
seen in the randomised controlled trials of circumcision in heterosexual men.
In contrast, there was no association whatsoever between
circumcision and HIV in more recent studies. The authors also found a
non-statistically significant reduction of 51% in HIV infections in circumcised
men in studies conducted in developing countries, where antiretroviral therapy
is less available.

The
authors suggested that higher rates of unsafe sex and resultant HIV and STI
infection in gay men since HIV treatment became available may have obscured the
relatively small benefit of circumcision.

They
also found a trend to more statistically significant results as study quality
increased, with a non-significant 32% reduction in HIV infection in circumcised
men seen in studies where circumcision and HIV infection were confirmed by
genital examination and testing.

A
separate editorial6
urged further trials to settle the question of whether circumcision offers any
protection against HIV to gay men once and for all. The authors commented that:
“only further research can answer…the question as to whether MSM should be
circumcised to reduce their HIV risk.”

However,
they also expressed concerns that such research might face opposition.

“The meta-analysis”, they say, “is likely to be
used by both advocates and detractors of clinical trial investment; some will
argue that the likely benefit is too modest to justify a multimillion dollar
trial while others will argue that only a clinical trial will answer this
important HIV prevention question.”

References

Buchbinder S et al. Sexual risk, nitrite inhalant use, and lack of circumcision associated with HIV seroconversion in men who have sex with men in the United States. J Acquir Immune Defic Syndr 39(1):82-89, 2005

Millett G et al. Circumcision status and HIV infection among black and latino men who have sex with men in 3 US cities. J Acquir Immune Defic Syndr 46: 643-50, 2007

Millett G et al. Circumcision status and risk of HIV and sexually transmitted infections among men who have sex with men: a meta-analysis. Journal of the American Medical Association 300(14):1674-1684, 2008

Vermund SH, Qian HZ Circumcision and HIV prevention among men who have sex with men: no final word. Journal of the American Medical Association 300(14):1698-1700, 2008

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member of your healthcare team for advice tailored to your situation.

The Community Consensus Statement is a joint initiative of AVAC, EATG, MSMGF, GNP+, HIV i-Base, the International HIV/AIDS Alliance, ITPC and NAM/aidsmap

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This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends
checking whether this is the most current information when making decisions that may affect your health.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member
of your healthcare team for advice tailored to your situation.